Gathering devices such as perfect binders, saddle stitchers and mailroom inserters may use hoppers or feeders to collect sheet material. A saddle stitcher or perfect binder may for example collect folded printed materials fed from hoppers or feeders onto a saddle or perfect binder conveyor, respectively, to form a magazine or other printed product. In the context of the present application, the term hopper and feeder are used synonymously.
U.S. Pat. No. 6,267,225 purportedly discloses a device for conveying thin workpieces for machines used in the printing technology field having at least one movable conveying element having an electrically insulating contact surface supporting at least one workpiece as it is being conveyed.
U.S. Pat. No. 6,616,134 discloses a device for electrostatically charging a multilayer material web includes electrostatic charge elements assigned to outer sides of the multilayer material web, the charge elements being disposed upline of an inlet of the multilayer material web into a cylinder.
U.S. Publication No. 2006/0180697 purportedly discloses an electrostatic charging system holds a film web to a roll without significant slippage, thus allowing for proper tension control of the web even with extreme differences in tension upstream and downstream of the motorized roll.